The present invention provides a precision press device and a press load control method thereof for downsizing a vacuum chamber in press work in the vacuum chamber, shortening a time required to reach a vacuum and further performing high accuracy pressure control. To downsize a chamber 16, 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 using the tubular shape of the chamber 16. A negative pressure 22 in the chamber 16 attracts the pressurized section 2 and the pressurizing section 1 to each other, 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. It is possible to control the load on the substrate or the like transferred by the press stage with high accuracy.