PROBLEM TO BE SOLVED: To achieve efficient customer management by one operator.SOLUTION: A merchandise sales data processor includes: a first operation reception part installed at a clerk side for registering merchandise; a display part for a clerk installed at the clerk side; a settlement part for performing price adjustment of registered merchandise; and a control part for executing merchandise registration processing for registering merchandise and settlement processing using the settlement part of the price adjustment of the registered merchandise. In the merchandise sales data processor, the control part executes merchandise registration processing to a second customer being the next customer during the execution of the settlement processing to a first customer.SELECTED DRAWING: Figure 1
