PURPOSE: To simplify the installation structure of the grille net of the front grille of a tractor.

CONSTITUTION: A grille net 4 to cover an intake opening 1, upper/lower pressing members 6, 7 which hold the periphery of the grill net 4 between an opening periphery part 3 so as to fix the periphery by a pin 5, and a grille stay 11 in which an interval between upper/lower stays 8, 9 attached along the upper/ lower pressing member 6, 7 are integrally formed by a connecting member 10, are arranged on the back side of the opening periphery 3 of a front grille 2 which forms the intake opening 1.