An automatic detection device for tape (Tc) comprising: a tape feeding mechanism that is configured to feed the tape (Tc), in which cavities (Ct) for component (e) accommodation are provided at a regular interval (Pc) and which has multiple empty cavities (Ct) on a leading end side, at a predetermined pitch, the tape feeding mechanism having multiple origin positions that are defined by positions of teeth of a sprocket at an interval (Pc) which is equal to or larger than the predetermined pitch; an origin position detector configured to detect each of the multiple origin positions of the tape feeding mechanism while the tape (Tc) is fed by the teeth of the sprocket ; a light amount detector configured to transmit light through the tape (Tc) and detect a transmitted light amount; the automatic detection device for tape being characterized by further comprising a leading end detection section configured to detect a leading end (Th) of the tape (Tc) fed by the tape feeding mechanism based on a detected light amount from the light amount detector ; a reference position determination section configured to determine a tape reference position, which is a reference position on the tape (Tc) in a fixed positional relationship with a first origin position (67ad1) being the origin position (67ad1) of the multiple origin positions of the tape feeding mechanism detected immediately before leading end detection by the leading end detection section , wherein the reference position determination section is configured to determine the tape reference position based on the first origin position (67ad1), a first position of the tape feeding mechanism , which is a position of the tape feeding mechanism at a time at which the leading end detection section detects the leading end (Th) of the tape, a feeding amount of the tape (Tc) from the first origin position (67ad1) to the first position, and an interval with an adjacent origin position (67ad2); and an interval calculating section configured to calculate an interval between the cavities (Ct) based on a detection cycle of the empty cavities (Ct) by the light amount detector after the reference position determination section determines the tape reference position. a tape feeding mechanism that is configured to feed the tape (Tc), in which cavities (Ct) for component (e) accommodation are provided at a regular interval (Pc) and which has multiple empty cavities (Ct) on a leading end side, at a predetermined pitch, the tape feeding mechanism having multiple origin positions that are defined by positions of teeth of a sprocket at an interval (Pc) which is equal to or larger than the predetermined pitch; an origin position detector configured to detect each of the multiple origin positions of the tape feeding mechanism while the tape (Tc) is fed by the teeth of the sprocket ; a light amount detector configured to transmit light through the tape (Tc) and detect a transmitted light amount; a leading end detection section configured to detect a leading end (Th) of the tape (Tc) fed by the tape feeding mechanism based on a detected light amount from the light amount detector ; a reference position determination section configured to determine a tape reference position, which is a reference position on the tape (Tc) in a fixed positional relationship with a first origin position (67ad1) being the origin position (67ad1) of the multiple origin positions of the tape feeding mechanism detected immediately before leading end detection by the leading end detection section , <EOS>