The invention concerns a vertical plate freezer for freezing foodstuffs, e.g. freezing fish on board a fishing vessel. The plate freezer has forks (7) provided with lower and rear coverings (10,11). The forks (7) have a toe (40) with a contact surface facing slantingly upwards and which can abut on a contact plate (17) with a contact surface facing slantingly downward so that water may easily run off the slantingly downward facing contact surface. The contact surface is preferably made of thermally insulating material. The coverings are fastened to support members (8,9) by means of transition elements (18) made of a thermally insulating material, so that the coldness from the coverings (10,11) is not conducted to the support members (8,9).