An apparatus for preventing bedsores associated with the ischia caused by the contact between the ischia and the seating mattress, which is likely to occur when the care-requiring patient with reduced muscle strength continues to sit down. An opening (2) is provided at a portion of a mattress (1) facing a sciata of a mattress to be used so that a user who has difficulty in changing a posture in a sitting position does not cause bedsore due to his / her sciatic bone. In order to remove the situation where the mattress is pressed or touched by the mattress, and to remove the so-called bottom feeling when using the mattress, the thickness of the mattress to be used is increased and the openings 2, 3 are directed toward the lower surface of the mattress. Drilling is performed to increase the opening area. In that case, the processing of a mattress having a large thickness is relatively expensive, so that a plurality of mattresses having a perforated hole in a general thickness are appropriately laminated. [Selection diagram] Fig. 1【課題】筋力の低下した要介護療養者が腰をかける姿勢を継続する場合に生じやすい坐骨と着座マットレスの接触により生じる坐骨に係わる床ずれ防止装置。【解決手段】着座位置で姿勢を変えることが困難な使用者が自らの坐骨による床ずれを起こさぬようにするために、使用するマットレス１の坐骨の対面する部分に開口２を設け、臀部の坐骨部近辺がマットレスによる圧迫や接触を受ける状況を取り除くと共に、マットレスを使用する際のいわゆる底つき感を除去するために、使用するマットレスの厚みを大きくすると共に開口２、３がマットレス下面に向かって開口面積を拡大してゆくように穿設する。その場合、厚みの大きなマットレスの加工が割高になるので、一般的な厚みのマットレスに適宜穿孔したものを複数積層して構成する。【選択図】図１
