Disk brake device and pair of brake pads

A disc brake device comprising:

• a disc rotor configured to be rotatable around its rotation axis;
• a pair of brake pads provided opposite each other on both sides of the disc rotor in an axial direction along the rotation axis;
• and
• a pressing mechanism configured to press the pair of brake pads against the disc rotor from both sides of the disc rotor using pistons provided opposite to each other on both sides of the disc rotor in the axial direction, wherein
• each brake pad of the pair of brake pads has a friction material facing a corresponding one of friction faces of the disc rotor, and
• a number of first slits provided in the friction material of one brake pad of the pair of brake pads and not passing through any one of pressing portions that are pressed by the pistons is different from a number of second slits provided in the friction material of the other brake pad and not passing through any one of the pressing portions that are pressed by the pistons,
• wherein each of the pair of brake pads has at least one slit in the corresponding friction material.