A reciprocating compressor comprising: a compression section which compresses gas; and a crank section which is separate from the compression section and has a crankshaft and a head case; and at least one first fastener (48, 151) fastening the compression section to the crank section, wherein the compression section comprises a wall body portion which includes a cylinder and constitutes a wall body of the compression section; a cylinder head (32, 33) attached to the cylinder; a piston which reciprocates within the cylinder; a piston rod coupled to the crankshaft by at least one second fastener provided within the head case, the piston rod being also coupled to the piston to drive the piston when the crank shaft is rotated; and at least one sealing member (45, 46, 47, 49) fixed to the wall body portion and disposed at the circumference of the piston rod, and wherein the wall body portion has a substantially plate-shaped boundary wall whose plate surfaces extend transverse to the length of the piston rod, one plate surface of the substantially plate-shaped boundary wall comprising a boundary with the crank section when the compression section and the crank section are fastened by the at least one first fastener, and the plate surface being a division surface when the crank section and the compression section are separated from one another, and the other plate surface of the substantially plate-shaped boundary wall being at the side of the substantially plate-shaped boundary wall which is opposite to the crank section; the substantially plate-shaped boundary wall being fixed to the crank section by the at least one first fastener directly fixing substantially plate-shaped boundary wall and the head case of the crank section, and a door in the head case at a location to expose the at least one second fastener such that the at least one second fastener is accessible and removable via said door. a compression section which compresses gas; and a crank section which is separate from the compression section and has a crankshaft and a head case; and at least one first fastener (48, 151) fastening the compression section to the crank section, wherein the compression section comprises a wall body portion which includes a cylinder and constitutes a wall body of the compression section; a cylinder head (32, 33) attached to the cylinder; a piston which reciprocates within the cylinder; a piston rod coupled to the crankshaft by at least one second fastener provided within the head case, the piston rod being also coupled to the piston to drive the piston when the crank shaft is rotated; and at least one sealing member (45, 46, 47, 49) fixed to the wall body portion and disposed at the circumference of the piston rod, and a wall body portion which includes a cylinder and constitutes a wall body of the compression section; a cylinder head (32, 33) attached to the cylinder; a piston which reciprocates within the cylinder; a piston rod coupled to the crankshaft by at least one second fastener provided within the head case, the piston rod being also coupled to the piston to drive the piston when the crank shaft is rotated; and at least one sealing member (45, 46, 47, 49) fixed to the wall body portion and disposed at the circumference of the piston rod, and wherein the wall body portion has a substantially plate-shaped boundary wall whose plate surfaces extend transverse to the length of the piston rod, one plate surface of the substantially plate-shaped boundary wall comprising a boundary with the crank section when the compression section and the crank section are fastened by the at least one first fastener, and the plate surface being a division surface when the crank section and the compression section are separated from one another, and the other plate surface of the substantially plate-shaped boundary wall being at the side of the substantially plate-shaped boundary wall which is opposite to the crank section; the substantially plate-shaped boundary wall being fixed to the crank section by the at least one first fastener directly fixing substantially plate-shaped boundary wall and the head case of the crank section, and a door in the head case at a location to expose the at least one second fastener such that the at least one second fastener is accessible and removable via said door.