Robot arm having a recessed portion with a drain

A robot comprising:

• a movable unit displaced in horizontal directions and having a recessed part opening upward in a vertical direction;
• a connector placed within the recessed part;
• a drain part that is a groove that communicates between a bottom portion of the recessed part and an outside of the movable unit and drains a liquid within the recessed part out of the recessed part;
• a base coupled to the movable unit;
• a pipe coupling the movable unit and the base and housing a wire inside;
• and
• a pipe connector placed within the recessed part and coupled to the pipe,
• wherein the movable unit has a first arm pivoting about a first axis along the vertical direction relative to the base, and a second arm pivoting about a second axis along the vertical direction relative to the first arm, and
• the recessed part is provided in the second arm.