A printer comprising: a mask holder configured to hold a mask; a board driver configured to cause a board to face the mask by driving the board below the mask; a squeegee driver configured to drive a squeegee provided above the mask; a pressure detector configured to detect a pressure received by the squeegee; and wherein the squeegee driver includes: a support member configured to support the squeegee so as to allow the squeegee to move up and down; a biasing member configured to bias the squeegee downward by generating biasing force between the support member and the squeegee, the biasing force changing in response to a difference in height between the support member and the squeegee; and a driving source configured to move the support member up and down, wherein the squeegee driver is configured to press the support member downward against the biasing force using the driving source while the squeegee contacts the mask so as to press the squeegee against the mask with a pressure responsive to the biasing force, the printer further comprises a clamp plate configured to clamp the board facing the mask from a horizontal direction, the squeegee driver is configured to perform pressure detecting operation of locating the support member at a predetermined height (hp) to press the squeegee against a second area of the upper surface of the mask, and then moving the support member parallel to the horizontal direction to cause the squeegee to slide on a first area of the upper surface of the mask being faced by the board, characterized by a controller configured to adjust the position of the board relative to the mask in a vertical direction using the board driver based on the pressure detector's detection result of a pressure received by the squeegee brought into contact with the first area of the upper surface of the mask, the controller being configured to adjust the position of the board relative to the mask in the vertical direction based on the pressure detector's detection result of a pressure received by the squeegee pressed against the first area, the clamp plate being configured to contact the lower surface of the mask, the second area being faced by the clamp plate, and the controller being configured to adjust the position of the board relative to the mask in the vertical direction based on a difference between a pressure received by the squeegee pressed against the second area and a pressure received by the squeegee sliding on the first area in the pressure detecting operation. a mask holder configured to hold a mask; a board driver configured to cause a board to face the mask by driving the board below the mask; a squeegee driver configured to drive a squeegee provided above the mask; a pressure detector configured to detect a pressure received by the squeegee; and wherein the squeegee driver includes: a support member configured to support the squeegee so as to allow the squeegee to move up and down; a biasing member configured to bias the squeegee downward by generating biasing force between the support member and the squeegee, the biasing force changing in response to a difference in height between the support member and the squeegee; and a driving source configured to move the support member up and down, wherein the squeegee driver is configured to press the support member downward against the biasing force using the driving source while the squeegee contacts the mask so as to press the squeegee against the mask with a pressure responsive to the biasing force, the printer further comprises a clamp plate configured to clamp the board facing the mask from a horizontal direction, the squeegee driver is configured to perform pressure detecting operation of locating the support member at a predetermined height (hp) to press the squeegee against a second area of the upper surface of the mask, and then moving the support member parallel to the horizontal direction to cause the squeegee to slide on a first area of the upper surface of the mask being faced by the board, characterized by a controller configured to adjust the position of the board relative to the mask in a vertical direction using the board driver based on the pressure detector's detection result of a pressure received by the squeegee brought into contact with the first area of the upper surface of the mask, the controller being configured to adjust the position of the board relative to the mask in the vertical direction based on the pressure detector's detection result of a pressure received by the squeegee pressed against the first area, the clamp plate being configured to contact the lower surface of the mask, the second area being faced by the clamp plate, and the controller being configured to adjust the position of the board relative to the mask in the vertical direction based on a difference between a pressure received by the squeegee pressed against the second area and a pressure received by the squeegee sliding on the first area in the pressure detecting operation.