A sales processing apparatus includes a processor and an input and output unit configured to perform an operation for a sales transaction processing. The processor is configured to acquire the time required for the input and output unit to perform the operation for the sales transaction processing of a sales transaction, then determine whether the time required for the input and output unit to perform the operation during the sales transaction exceeds a reference time for the input and output unit to perform the operation. A notification is output if the time required for the input and output unit to perform the operation during the sales transaction exceeds the reference time.