Stair exerciser apparatus

A stair exerciser apparatus includes a frame having a pair of inclined supports, a drive mechanism, a plurality of stairs and an electromagnetic resistance device. The stairs are coupled to the drive mechanism for traveling around the pair of inclined supports. The electromagnetic resistance device is coupled to the drive mechanism to control the running speed of the stairs. The electromagnetic resistance device has a flywheel, an electromagnet and a brake unit. The electromagnet is coupled to the brake unit for controlling rotation resistance of the flywheel. The brake unit has a brake block for stopping the flywheel to stop the stairs. The brake unit is pivotally rotatable between a non-braking position where the brake block is pulled away from the flywheel when the electromagnet is energized and a braking position where the brake block is pulled to stop the flywheel when the electromagnet is loss of power.