Alignment device and substrate processing apparatus

An alignment device comprising:

• a plurality of holders respectively configured to be rotatable about a rotational center axis in a vertical direction while holding a substrate having a portion for detection substantially in a horizontal attitude, and arranged to line up in a vertical direction;
• a shaft member having an axis that extends in the vertical direction;
• a rotation driver that rotates the shaft member with the axis as a center;
• a plurality of detectors provided to respectively correspond to the plurality of holders, and respectively configured to detect the portions for detection of the substrates held by the corresponding holders;
• a plurality of transmission switchers that are provided to respectively correspond to the plurality of holders, and switch to a transmission state in which rotation of the shaft member is transmitted to the corresponding holder and a non-transmission state in which rotation of the shaft member is not transmitted to the corresponding holder, wherein
• the plurality of transmission switchers are configured to switch from the transmission state to the non-transmission state based on a detection result by the corresponding detector when a portion for detection of the substrate rotated by the corresponding holder is positioned in a predetermined common direction with respect to the rotational center axis.