A solenoid valve includes: a cylindrical spool that has an annular groove in an outer surface and moves along an axial direction under a driving force generated by a current being applied to a solenoid part; a cylindrical sleeve that has a through-hole capable of communicating with the annular groove and houses the spool; and an urging member that urges the spool by an urging force acting in a direction opposite from a direction in which the driving force is generated. When no current is applied to the solenoid part, a part of the through-hole communicates with the annular groove. When a current is applied to the solenoid part, an area of communication between the through-hole and the annular groove increases as the spool moves under the driving force acting against the urging force.