Abstract: A recorder including an A/D converter for converting analog measured input signals into digital input sampling data for a predetermined sampling period, for processing the converted data by a microprocessor, and for subsequently driving a recording head to make a recording on a recording paper. A paper end detecting sensor is carried on the head, and the microprocessor is caused to compute a recording position signal according to the measured input signals on the basis of the sampling data; to correct the recording position signal on the basis of both a reference width for the recording paper and the paper width, which is measured as a result of detecting the 0% and 100% ends of the recording paper by the sensor, thereby to produce a recording position correcting signal according to the extension or contraction of the recording paper; to control the position of the recording head in accordance with the recording position correcting signal; and to make a recording on the recording paper by the recording head.