To provide a solenoid valve with improved productivity.

The solenoid valve (always-open solenoid valve 1) includes a valve seat member 4, a valve body member 5 which moves forward/backward so as to be brought into contact with the valve seat member 4, and a tubular body part 3 for housing the valve seat member 4 and the valve body member 5. The body part 3 includes a tubular first body part 10 which holds the valve body member 5 so as to move forward/backward, and a second tubular body part 20 which is formed separately from the first body part 10 to hold the valve seat member 4. The first body part 10 and the second body part 20 are connected together when the end part of second body part 20 enters the end part of the first body part 10 for engagement. The wall of the connection part 22 is formed thinner than the wall of a portion (valve seat holding part 21) that holds the valve seat member 4, and has a through hole 22a that penetrates in the direction crossing the moving direction of the valve body member 5.