Computer mouse with dust-proof block

A computer mouse comprising:

• an outer housing defining a receiving space;
• a left button and a right button received in the receiving space of the outer housing;
• a middle button hole cooperatively defined by and located between the left button and the right button;
• a middle button arranged in the middle button hole between the left button and the right button;
• a bottom cover connected to the outer housing;
• and
• a middle button bracket comprising:
• a dust-proof block comprising:
• a main body comprising an upper surface;
• a raised portion protruding from the upper surface of the main body;
• and
• a middle button receiving slot extending through the main body and the raised portion, the middle button being arranged in the middle button receiving slot, the raised portion being fitted in the middle button hole, a top surface of the raised portion being substantially flush with outer surfaces of the left button and the right button, and a sidewall of the raised portion being in contact with a sidewall of the middle button hole;
• and
• a plurality of elastic components arranged between the main body and the bottom cover, a first end of each of the elastic components abutting against a lower surface of the main body, and the elastic components applying a pushing force to the dust-proof block, thereby keeping the top surface of the raised portion substantially flush with the outer surfaces of the left button and the right button when no button being pressed and substantially flush with the outer surface of the left button or the right button when the left button or the right button is pressed.