A rubber composition containing: 100 parts by mass of a sulfur-modified chloroprene rubber; 25 to 55 parts by mass of carbon black having an average particle diameter of 70 nm or less; and more than 0 parts by mass and 15 parts by mass or less of a diene-based rubber other than a chloroprene rubber, in which the sulfur-modified chloroprene rubber has a functional group A represented by a specific formula (A) and positioned at a molecular terminal, and in the sulfur-modified chloroprene rubber, a mass ratio B/A of a content of a functional group B represented by a specific formula (B) and positioned at a molecular terminal with respect to a content of the functional group A is 12.00 or less, and a total amount of the functional group A and the functional group B is 0.10 to 1.00% by mass.