To eliminate a defect of a conventional reciprocating pump while making the most of an advantage of the reciprocating pump.

This reciprocating pump 10 includes a cylinder 14 having a closed inside partitioning chamber 18. A piston assembly 12 is installed in the partitioning chamber so as to be reciprocatable in the opposed straight line direction. A linear magnetic driving device 50 derives a linearly moving magnetic field for moving the piston assembly by the sweep volyame in the opposed straight line direction. A seal member 17 is arranged for dividing the partitioning chamber between the cylinder and the piston assembly into a distribution chamber 20 and an accumulating chamber 22. An inlet conduit 30 communicates with the distribution chamber, and an outlet conduit 32 communicated with the distribution chamber for pointing a force feed liquid to the outside of the partitioning chamber when the piston assembly moves by the sweep volume at a distribution stroke. An energy storage release medium communicates with the accumulating chamber, and stores energy as a result of moving the piston assembly in the direction for separating from the distribution end of the partitioning chamber, and releases the stored energy when the piston assembly moves in the direction toward the distribution end.