To provide a dry type and single plate type braking device actuated with no excitation and an assembling method, wherein an adjustment of a clearance dimension between an abutment surface of a yoke and an armature is not required on the part of clients.

When assembling a dry type and single plate type braking device 1 actuated with no excitation after disposing a spacer 9 between the yoke 6 and the armature 4, the armature 4 and the yoke 6 are temporarily fastened by a temporal tacking screw 88 under a condition that the armature 4 is being attracted toward the yoke 6. Further, a hub 3 is placed on the armature 4, and after the hub 3 is connected with a rotating shaft 2, the temporal tacking screw 88 is removed, then the spacer 9 is moved away. As a result, a predetermined dimensional clearance corresponding to the thickness of the spacer 9 can be maintained between the yoke 6 and the armature 4.