diff --git a/crates/swc_ecma_parser/src/lexer/number.rs b/crates/swc_ecma_parser/src/lexer/number.rs
index febdd44277ca..3d3117b3866a 100644
--- a/crates/swc_ecma_parser/src/lexer/number.rs
+++ b/crates/swc_ecma_parser/src/lexer/number.rs
@@ -137,13 +137,22 @@ impl<'a, I: Input> Lexer<'a, I> {
             };
 
             let exp = self.read_number_no_dot(10)?;
-            let flag = if positive { '+' } else { '-' };
 
-            raw_val.push(flag);
-            write!(raw_val, "{}", exp).unwrap();
+            val = if exp == f64::INFINITY {
+                if positive && val != 0.0 {
+                    f64::INFINITY
+                } else {
+                    0.0
+                }
+            } else {
+                let flag = if positive { '+' } else { '-' };
+
+                raw_val.push(flag);
+                write!(raw_val, "{}", exp).unwrap();
 
-            // TODO:
-            val = raw_val.parse().expect("failed to parse float literal");
+                // TODO:
+                raw_val.parse().expect("failed to parse float literal")
+            }
         }
 
         self.ensure_not_ident()?;
@@ -478,6 +487,51 @@ mod tests {
         assert_eq!(1e30, num("1e30"));
     }
 
+    #[test]
+    fn num_very_big_exp() {
+        const LARGE_POSITIVE_EXP: &str =
+            "1e100000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000";
+        const LARGE_NEGATIVE_EXP: &str =
+            "1e-10000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             000000000000000000000000000000000000000000000000000000";
+        const ZERO_WITH_LARGE_POSITIVE_EXP: &str =
+            "0e100000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000";
+        const ZERO_WITH_LARGE_NEGATIVE_EXP: &str =
+            "0e-10000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             000000000000000000000000000000000000000000000000000000";
+        const LARGE_MANTISSA_WITH_LARGE_NEGATIVE_EXP: &str =
+            "10000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             000000000000000000000000000000000000000000000000000000\
+             e-100000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             00000000000000000000000000000000000000000000000000000000000000000\
+             000000000000000000000000000000000000000000000000000000";
+
+        assert_eq!(num(LARGE_POSITIVE_EXP), INFINITY);
+        assert_eq!(num(LARGE_NEGATIVE_EXP), 0.0);
+        assert_eq!(num(ZERO_WITH_LARGE_POSITIVE_EXP), 0.0);
+        assert_eq!(num(ZERO_WITH_LARGE_NEGATIVE_EXP), 0.0);
+        assert_eq!(num(LARGE_MANTISSA_WITH_LARGE_NEGATIVE_EXP), 0.0);
+    }
+
     #[test]
     fn num_big_many_zero() {
         assert_eq!(