A latex for dip forming and a sulfur-based crosslinking agent, and has a pH of 9.5-11, the latex containing a copolymer having 40-80% by weight of conjugated diene monomer units (A) that contain a butadiene unit and an isoprene unit, 10-45% by weight of ethylenically unsaturated nitrile monomer units (B), and 2-15% by weight of ethylenically unsaturated acid monomer units (C), the ratio between the butadiene unit content and the isoprene unit content being 40:60 to 95:5 expressed in terms of weight.