A precision press device and a press load control method is provided for downsizing a vacuum chamber in press work in the vacuum chamber, shortening a time required to reach a vacuum and performing high accuracy pressure control. A pressure sensor is set up outside the chamber 16 and a cylinder chamber 17 is formed to allow a tubular plunger 7 to slide up and down. A negative pressure 22 in the chamber 16 attracts the pressurized section 2 and the pressurizing section 1, but by injecting an equivalent pressure 19 of a fluid into the cylinder chamber 17, pushing out the tubular plunger 7, the attractive forces are canceled out.