Detection device and detection method

A detection device that detects a position of a leading end of a tip for executing an operation on a cell via the leading end, the tip including the leading end in a lower portion thereof, the detection device comprising:

• a light source that outputs light in a lateral direction such that the light has a width when viewed along an up-and-down direction;
• a movement mechanism that moves the tip;
• and
• a detector that detects the light output from the light source, wherein
• the light output from the light source until being detected by the detector includes first light and second light that advance in respective lateral directions that are different from each other,
• the movement mechanism moves the tip such that a part of the first light and a part of the second light are blocked by the leading end and such that the leading end is positioned in a width of the first light and in a width of the second light at respective different timings,
• the width of the first light is larger than a fluctuation width of a position of the leading end in a direction of the width of the first light,
• the width of the second light is larger than a fluctuation width of a position of the leading end in a direction of the width of the second light,
• the detection device further comprises a mirror that reflects light from the light source toward the detector, the first light is light directing from the light source to the mirror, and the second light is light directing from the mirror to the detector, and
• the detector detects the first light whose part is blocked by the leading end and the second light whose part is blocked by the leading end.