To provide a chamber device capable of reducing pressure pulsation propagated from a piping interior to a canister during opening and closing driving without enlarging a shape.

The solenoid valve device includes a valve case part VC having a pressure introduction port 11 and a pressure discharge port 12 and using an interior as a chamber 13, and a solenoid valve part having a valve 14 opening and closing a space between the chamber 13 and the pressure discharge port 12 by electromagnetic force. A fluid diffusion member 16 of a porous hole structure is installed in an inlet part of the chamber 13.