Glass plate manufacturing method and manufacturing device thereof

A glass ribbon (G) is formed in a forming zone (11), the glass ribbon (G) is conveyed in the longitudinal direction by a conveying device (14), the glass ribbon (G) is cut in the width direction by a cutting device (2) to cut out a glass plate (g), the cut-side end (Gt) of the glass ribbon (G) and the glass plate (g) are used as measurement objects, the temperature of the measurement objects (Gt, g) is measured, and the glass ribbon (G) is conveyed in the longitudinal direction by the conveying device (14). The defect occurring in the measurement object (Gt, g) is detected on the basis of the measurement result of the measurement object (Gt, g). 在成形区(11)成形玻璃带(G)并且利用搬运装置(14)将该玻璃带(G)在长度方向上搬运的同时，利用切断装置(2)将玻璃带(G)沿着宽度方向切断而切出玻璃板(g)，之后将玻璃带(G)的切断侧端部(Gt)以及玻璃板(g)作为测定对象，对该测定对象(Gt、g)测定温度，基于该测定对象(Gt、g)的测定结果对在该测定对象(Gt、g)产生的不良进行检测。