A liquid feeding device (1, la, 1b) comprising: a discharge channel; a pump part including a plurality of plunger pumps connected in series or in parallel to each other and discharging liquid to the discharge channel, at least one of the plurality of plunger pumps being a closed pump not connected to the discharge channel during a non-discharge time, the non-discharge time being a time in which the closed pump does not execute a discharge process for discharging liquid to the discharge channel; a feeding pressure sensor detecting pressure in the discharge channel as a feeding pressure; a non-discharge pressure sensor detecting pressure in the pump chamber of the closed pump during the non-discharge time as non-discharge pressure; a pre-compression part configured to cause the closed pump to execute a pre-compression process after completing a suction process for sucking liquid into the pump chamber and during the non-discharge time based on output of the feeding pressure sensor and output of the non-discharge pressure sensor, the pre-compression process being a process to perform a discharge operation until the non-discharge pressure reaches substantially the same as the feeding pressure; and a pre-compression speed determination part configured to determine a speed of the discharge operation of the closed pump in the pre-compression process based on the feeding pressure and based on a correlation specified so that a maximum speed of the discharge operation of the closed pump in the pre-compression process becomes higher as the feeding pressure is higher, wherein the pre-compression part is configured to cause the closed pump to perform the discharge operation at a speed determined by the pre-compression speed determination part in the pre-compression process. a discharge channel; a pump part including a plurality of plunger pumps connected in series or in parallel to each other and discharging liquid to the discharge channel, at least one of the plurality of plunger pumps being a closed pump not connected to the discharge channel during a non-discharge time, the non-discharge time being a time in which the closed pump does not execute a discharge process for discharging liquid to the discharge channel; a feeding pressure sensor detecting pressure in the discharge channel as a feeding pressure; a non-discharge pressure sensor detecting pressure in the pump chamber of the closed pump during the non-discharge time as non-discharge pressure; a pre-compression part configured to cause the closed pump to execute a pre-compression process after completing a suction process for sucking liquid into the pump chamber and during the non-discharge time based on output of the feeding pressure sensor and output of the non-discharge pressure sensor, the pre-compression process being a process to perform a discharge operation until the non-discharge pressure reaches substantially the same as the feeding pressure; and a pre-compression speed determination part configured to determine a speed of the discharge operation of the closed pump in the pre-compression process based on the feeding pressure and based on a correlation specified so that a maximum speed of the discharge operation of the closed pump in the pre-compression process becomes higher as the feeding pressure is higher, wherein the pre-compression part is configured to cause the closed pump to perform the discharge operation at a speed determined by the pre-compression speed determination part in the pre-compression process. <EOS>