To provide a gas-liquid separator capable of separating an upstream side cylindrical filter and a downstream side cylindrical filter.

A swirl vane 12 is disposed in an annular space 11 formed by a main body 1 and an exhaust pipe 10. An upper part of the swirl vane 12 is connected to an inlet 6 and its upper part is connected to an outlet 7 through a hole inside the exhaust pipe 10. A liquid reservoir chamber 15 is formed at an upper part of the annular space 11 and a lower end of the liquid reservoir chamber 15 is connected to a discharge port 8. An upstream side cylindrical filter 24 is disposed between the exhaust pipe 10 and the liquid reservoir chamber 15 and a downstream side cylindrical filter 22 is disposed inside the upstream side cylindrical filter 24. An upper end of the upstream side cylindrical filter 24 is fixed by welding to a valve seat 16 and a lower end of the upstream side cylindrical filter 24 is fixed by welding to a plug 23, the lower end of the downstream side cylindrical filter 22 is fixed by welding to a second plug 25 connected by screw coupling to the plug 23, and an upper end of the downstream side cylindrical filter 22 is butted and connected to the valve seat 16.