To reduce worsening of combustion accompanying EGR by controlling a piston temperature so as to reduce NOx generation amount and reducing the demanded EGR amount even in a region on a high load and high speed rotation side in a stratified combustion region in a cylinder injection type internal combustion engine performing stratified combustion.

In a piston temperature controller in the cylinder injection type internal combustion engine provided with a piston cooling means and performing stratified combustion accompanying EGR in a low load and low speed rotation region and homogeneous combustion in the other region, piston cooling by the piston cooling means is stopped on a low load and low speed rotation side in the stratified combustion region, and piston cooling by the piston cooling means is performed on the high load and high speed rotation side in the stratified combustion region.