In a transmission chain having series-connected a TSC unit, an encoder, a transmission path, a decoder, and an up-converter, characteristic value extracting units are connected to input/output points A, B, C, and D of these transmission processing units respectively. Each characteristic value extracting unit extracts characteristics like an average value m and a variance σ2 of luminance of a picture, for example. These characteristic values are transmitted to a central monitoring unit via a low-speed line. A characteristic value comparator compares the characteristic values. When a difference equal to or larger than a predetermined threshold value has occurred in the characteristic values, the characteristic value comparator decides that an abnormality has occurred in the image in transmission. According to the present invention, it is possible to provide an apparatus for assessing quality of a picture in transmission and an apparatus for remote-monitoring picture quality of a picture in transmission that are capable of assessing the picture quality of a transmission picture in high precision, during an actual transmission of the picture.