To obtain a disc brake unit of a pin-slide type having a simple structure and no fear of dragging a brake pad, securing high efficiency and stabilization of brake performance.

The disc brake unit is configured so that at least one of two pin-slide mechanisms that are in a pair and isolated from each other towards the peripheral direction of a rotor is guided so as to freely slide by a contact of each metal in the direction where a caliper 20 is disposed in parallel with the rotor shaft direction against a carrier 10, and also configured so that an inner-brake pad 60 and an outer-brake pad 70 are hung at a hanger pin 82 mounted to the caliper 20 and both end faces of the peripheral direction of the rotor are supported by the carrier 10.