PURPOSE: To enable a label, a seal or a tape with an adhesive to be repeatedly used to be laminated or peeled many times by using a release agent which contains an N-long-chain alkyl maleimide or a single monomer of an N-long- chain alkyl maleimide or copolymer of the monomer to be copolymerized with them as main ingredients.

CONSTITUTION: A desired area is coated with a release agent which contains an N-long-chain alkyl maleimide represented by a formula I or a single monomer of an N-long-chain alkyl maleimide or a copolymer of the monomer to be copolymerized with them as main ingredients (where R in the formula is an alkyl group). As one example, cover plates 3, 4 are connected to the upper sides of the side plates 2 of a corrugated fiberboard tote box 1, and superposed to form a cover covering the upper surface of the box 1. The entire surfaces of both the plates 3, 4 and the upper halves 6 of side boards 5 are coated with back release agent. A Kraft tape 7 is laminated on the boundary between the plates 3 and 4 from the surface 6 of the board 5 and the surface 6 of the board 5 of the opposite side, the box 1 is sealed, and an address label 8 is laminated on the surface of the plate 3.