In supply of feedback data to improve a positional deviation quantity and a deviation state of a soldering paste printed on individual substrates held on the carrier, a plurality of average values of individual positional deviation for each of the individual substrates are obtained, and then, if the deviation value ΔM indicating a difference between the maximum value Mmax and the minimum value Mmin of the plurality of average values M of individual positional deviation is less than or equal to the tolerance value Δ(t), an intermediate value of the maximum value Mmax and the minimum value Mmin is obtained, and the positioning parameters of the mask plate and the carrier are corrected based on the intermediate value (Mmax+Mmin)/2.