PURPOSE: To attain reduction in intake resistance after a warm-up process in a device arranging a flat electric heating element transversely relative to a fuel flow direction on the downstream side of a fuel-injection nozzle, by fitting an electric heating element at a rest position along the fuel flow direction so as to be movable.

CONSTITUTION: This intake device for internal combustion engine involving 4 valves for each cylinder is provided with a lattice-shaped or honey-combs- shaped flat plate body electric heating element 5 rotatably-provided between intake valves 2, 3 and a fuel-injection valve 4 inside an intake channel 1. The electric heating element 5 is constituted of a electrically resistant material having a positive resistance-temperature coefficient and is energizingly-controlled according to at least one of internal combustion engine operating parameters of such as rotational speed, load, and the temperature of cooling water. The heating element 5 is retained by a heating element shaft 7 penetrating through the wall 6 of the intake channel 1 and moved to a rest position indicated by a solid line after completion of warm-up of the device with a adjusting lever 8 fixed at the external free end part of the shaft 7.