A disc brake device (1, 201, 301, 401, 501) comprising: a disc rotor which rotates around a rotational axial line; a friction pad (3, 4) which faces a friction surface of the disc rotor; a caliper which is capable of pressing the friction pad to the friction surface of the disc rotor; a mounting in which the caliper is provided; and a caliper slide mechanism (7, 207, 307, 407, 507) which supports the caliper on the mounting in a manner enabling slide movement via a slide pin inserted in a guide section (74, 475, 575) provided in a hole section of the caliper or the mounting and having two support parts (75a, 75b, 475a, 475b, 575a, 575b) that support both end sections of the slide pin to guide slide movement of the slide pin, characterized in that the caliper slide mechanism has a variable mechanism (74, 474, 574) which makes a permissible swing angle of the slide pin with respect to a slide movement direction variable in response to a braking action along with slide movement of the caliper by changing an interval between the two support parts of the guide section along the slide movement direction and by making the interval in the braking state where the friction pad is pressed to the friction surface of the disc rotor shorter than the interval in the non-braking state where the friction pad is separated from the friction surface of the disc rotor, and the variable mechanism has a variable mechanism moving element in which one of the two support parts is provided and a variable mechanism pressure chamber which is supplied with a hydraulic medium and generates force to make the variable mechanism moving element approach the other of the two support parts. a disc rotor which rotates around a rotational axial line; a friction pad (3, 4) which faces a friction surface of the disc rotor; a caliper which is capable of pressing the friction pad to the friction surface of the disc rotor; a mounting in which the caliper is provided; and a caliper slide mechanism (7, 207, 307, 407, 507) which supports the caliper on the mounting in a manner enabling slide movement via a slide pin inserted in a guide section (74, 475, 575) provided in a hole section of the caliper or the mounting and having two support parts (75a, 75b, 475a, 475b, 575a, 575b) that support both end sections of the slide pin to guide slide movement of the slide pin, characterized in that the caliper slide mechanism has a variable mechanism (74, 474, 574) which makes a permissible swing angle of the slide pin with respect to a slide movement direction variable in response to a braking action along with slide movement of the caliper by changing an interval between the two support parts of the guide section along the slide movement direction and by making the interval in the braking state where the friction pad is pressed to the friction surface of the disc rotor shorter than the interval in the non-braking state where the friction pad is separated from the friction surface of the disc rotor, and the variable mechanism has a variable mechanism moving element in which one of the two support parts is provided and a variable mechanism pressure chamber which is supplied with a hydraulic medium and generates force to make the variable mechanism moving element approach the other of the two support parts.