A rotary solenoid for stabilizing performance is provided. A rotary solenoid 10 includes a pair of the first yoke 21 and the second yoke 22 placed oppositely in a rotor 24 providing a pair of magnetic poles by a permanent magnet, a core 23 enclosed by the first yoke 21 and the second yoke 22, and a coil 25 wound around the core 23 and forming a pair of magnetic poles in the first yoke 21 and the second yoke 22 by supplying electricity. These first yoke 21, second yoke 22, core 23, and coil 25 are resin-molded. A projecting portion 26a is provided in an outer surface on the opposite side of enclosing the core 23 by the first yoke 21 and the second yoke 22.