An extrusion press includes a means which can prevent phenomena in which a billet is blown out during an extrusion process as well as prevent billet blowout with a simple and inexpensive constitution. The extrusion press drives a main cylinder device to extrude, by a stem , a billet filled into a container from a die and form a product. A gap measurement means that measures a gap arising at the container seal surface formed by pressing the die side end surface of the container against the container side end surface of the die is provided on an end platen on the outer edge part of the container side end surface of the die. When the gap arising during the extrusion process is measured and the measured value is within a predetermined range of allowable values, a set value for the extrusion rate is lowered and a warning is issued. When the measured value exceeds the predetermined allowable values, the extrusion process is stopped.