An end mill body comprises: bottom blades formed at ridgelines where gashes and tip flank faces intersect, the gashes are formed at the tips of chip discharge grooves. At least one of the bottom blades serves as a long bottom blade that extends toward an inner peripheral side longer than the remaining bottom blades. The end mill body also has coolant holes formed between the chip discharge grooves. A coolant hole which is located between a chip discharge groove of a gash and a chip discharge groove located behind the chip discharge groove in a rotational direction is open to the tip clearance face of the long bottom blade. A coolant hole which is located between the chip discharge groove of the gash and a chip discharge groove located in front of the chip discharge groove in the rotational direction is open to the gash of the long bottom blade.