A linear solenoid valve includes a solenoid having a coil wound around a coil bobbin, a fixed core, and a movable core for being attracted to the fixed core when the coil is energized, and a valve mechanism having a valve element for selectively bringing an inlet port and an outlet port into and out of fluid communication with each other responsive to a displacement of the movable core. The movable core has a nonmagnetic layer formed on an outer surface thereof and having a predetermined thickness.