To provide a coil assembly holding structure which securely holds a coil assembly in the axial direction and reduces the number of components.

An end plate 14, in which a salient part 4Ce of a recess and salient part 4C formed at a bottom part of a coil housing 4 is disposed as an elastic deformation part at one axial end part of a coil assembly 2, is elastically pressed in the axial direction of the coil assembly 2. Pressing the end plate 14 in the way causes a bottom part 13C of a coil yoke 13, which is positioned at the other axial end part of the coil assembly 2, to be pressed against a bottom surface of a receiving recess part 3C of a valve body 3. Thus, the coil assembly 2 is securely held in the axial direction between the valve body 3 and the coil housing 4.