According to a fixing device of the present invention, a screw penetrates through a first fixing hole provided at a first fixing section and a second fixing hole provided at a second fixing section to be coupled with a weight measuring machine, and is tightened with a nut, so that the first fixing section is fixed to the second fixing section. In addition, at least one clearance of the first fixing hole and the second fixing hole is configured to be bigger than an assembly tolerance of the two fixing holes. Using this structure, the fixing device, which can accommodate constructive variations of the fixing section of the weight measuring machine and maintain excellent detecting accuracy, and a weight measuring apparatus using the same can be provided.