Frame of work vehicle and work vehicle

A frame of a work vehicle, the frame comprising:

• an upper plate that has a plate shape and that forms an upper surface of the frame extending along a front-rear direction;
• a lower plate that has a plate shape and that is opposite to the upper plate in an up-down direction and forms a lower surface of the frame;
• a vertical wall that is disposed between the upper plate and the lower plate in the up-down direction and connects the upper plate to the lower plate;
• and
• an attachment portion to which an actuator that moves work equipment in the up-down direction is attached,
• wherein at least one of the upper plate and the lower plate includes
• a center portion,
• a first extension portion extending from the center portion in the front-rear direction,
• a second extension portion extending from the center portion in a left-right direction, and
• a continuous portion connecting the first extension portion to the second extension portion, and
• wherein the attachment portion is provided at both ends of the second extension portion in the left-right direction.