This paper describes simulation of steady-state temperature rise on transcutaneous energy transmission by non-contact energy transmitting coils. Electrical energy can be transmitted transcutaneously by means of the inductive coupling between two coils, one of which is located on the skin and the other is implanted inside the body. We calculated temperature rise by the finite element method (FEM), considering the cooling effect of blood flow. Spacing the two coils further apart increases the transmitting loss i.e. heating value of the coils and raises the heat radiation effect around the coils. By simulating with various values of coil spacing, we have estimated the optimum coil spacing which minimizes the temperature rise. Theresults have revealed that the optimum spacing depends on the thickness of a layer of subcutaneous tissues in which the cooling effect is expected to be less than in normal tissues. In a typical case the optimum spacing is in the range of 9–13 mm.