To freely apply a design on the total surface of a plastic product.

On a thermoplastic resin sheet or an elastic rubber sheet, an image is recorded with a recording material containing an evaporative dyeing agent, and thus, a transfer sheet is formed, and after widening and fixing the transfer sheet, the transfer sheet is placed on a plastic product while heating it, and a gap between the transfer sheet and the plastic product is vacuumized. By this method, while the transfer sheet is being joined to the plastic product, the transfer sheet is simultaneously heated by a non-contact method.