Two-stage switching valve

A two-stage switching valve comprising:

• a valve seat in an annular shape projected radially inward from a passage wall;
• a valve element located on an upstream side of the valve seat and movable in a flow direction, the valve element being configured to be biased with a fluidic pressure from an upstream side toward a downstream side;
• and
• a spring biasing the valve element toward the upstream side, wherein
• the valve element has a through hole, which is configured to pass fluid between the upstream of the valve element and the downstream of the valve element in a state the valve element is seated on the valve seat,
• the valve element is configured to switch between a large opening state and a small opening state, wherein
• in the large opening state, the valve element is lifted from the valve seat to pass fluid around an outer circumferential periphery of the valve element and to pass through the through hole, and
• in the small opening state, the valve element is seated on the valve seat to pass fluid through the through hole, wherein
• the valve element is supported and slidable at the outer circumferential periphery on a guide surface, which is formed on the passage wall.