A horizontal plate pressure filter, comprising a plurality of superimposed filter plates for forming filter chambers between at least two adjacent filter plates; a head plate arranged above the uppermost filter plate; an opening actuator arrangement for providing an opening movement and a closing movement; an opening mechanism coupled to the opening actuator arrangement and to the head plate, the opening mechanism being configured to mechanically transmit the opening movement and the closing movement between the opening actuator arrangement and the head plate, so as to move the head plate away from, and respectively towards the uppermost filter plate; a limited clearance arrangement coupled between the head plate and the uppermost filter plate, and respectively, between adjacent filter plates, wherein the limited clearance arrangement being configured to - allow the head plate to abut the uppermost filter plate, and respectively, adjacent filter plates to abut each other when moved towards each other, and - allow a limited clearance to be formed between the head plate and the uppermost filter plate, and respectively, between adjacent filter plates when moved away from each other, and a vertically extending guide arrangement for laterally supporting the filter plates and the head plate, and enabling the filter plates and the head plate to move away and towards from each other along said guide arrangement, and a support structure for selectively rigidly securing the head plate thereto at least at a closed position of the head plate, the support structure comprising at least two vertically extending support columns positioned at opposite lateral sides of the head plate characterized by the opening mechanism extending vertically at a plurality of distinct positions, preferably along the support columns, and wherein the opening actuator arrangement comprises an electric motor mechanically operationally coupled to the opening mechanism, at a plurality of distinct positions thereof. a plurality of superimposed filter plates for forming filter chambers between at least two adjacent filter plates; a head plate arranged above the uppermost filter plate; an opening actuator arrangement for providing an opening movement and a closing movement; an opening mechanism coupled to the opening actuator arrangement and to the head plate, the opening mechanism being configured to mechanically transmit the opening movement and the closing movement between the opening actuator arrangement and the head plate, so as to move the head plate away from, and respectively towards the uppermost filter plate; a limited clearance arrangement coupled between the head plate and the uppermost filter plate, and respectively, between adjacent filter plates, wherein the limited clearance arrangement being configured to - allow the head plate to abut the uppermost filter plate, and respectively, adjacent filter plates to abut each other when moved towards each other, and - allow a limited clearance to be formed between the head plate and the uppermost filter plate, and respectively, between adjacent filter plates when moved away from each other, and - allow the head plate to abut the uppermost filter plate, and respectively, adjacent filter plates to abut each other when moved towards each other, and - allow a limited clearance to be formed between the head plate and the uppermost filter plate, and respectively, between adjacent filter plates when moved away from each other, and a vertically extending guide arrangement for laterally supporting the filter plates and the head plate, and enabling the filter plates and the head plate to move away and towards from each other along said guide arrangement, and a support structure for selectively rigidly securing the head plate thereto at least at a closed position of the head plate, the support structure comprising at least two vertically extending support columns positioned at opposite lateral sides of the head plate characterized by the opening mechanism extending vertically at a plurality of distinct positions, preferably along the support columns, and wherein the opening actuator arrangement comprises an electric motor mechanically operationally coupled to the opening mechanism, at a plurality of distinct positions thereof.