A solenoid valve is formed by engaging locking protrusions with engagement holes and thereby joining a valve body and a magnetic cover to each other. A top wall of the magnetic cover is formed by a pair of bent portions that extend from a pair of respective sidewalls of the magnetic cover and that are bent toward the space between the sidewalls. The bent portions are fastened to each other in the width direction Wd by a circuit board spacer (first fastening member), and the circuit board spacer and the valve body are fastened to each other in the axial direction Ld by a connector cover.