To provide a solenoid valve for gas capable of being operated at a high speed with low leakage of gas.

A main body 11 includes an inlet port 15 and an outlet port 16 and a valve sheet 18. The back pressure chamber 23 is filled with gas flowing from the inlet port 15 and the pressure of the gas is energized in the direction to make the main valve 12 seated to the valve sheet 18. A pilot mechanism 13 includes a pilot valve 29 and a pilot valve seat 30. As the pilot valve 29 is unseated from the pilot valve seat 30, gas introduced to the back pressure chamber 23 is discharged. An electromagnetic part 14 lets the pilot valve 29 move in the unseating direction. On the central line of the main valve 12, the passage 24 connecting the back pressure chamber 23 and the pilot valve seat 30 is formed in the main valve 12 so as to be positioned in the passage 24. On the leading side of the pilot valve 29, an engaging part 31 is fixed which works to energize the main valve 12 in the unseating direction by engaging with the main valve 12 when the pilot valve 29 is unseated.