Neuromuscular diseases such as amyotrophic lateral sclerosis (ALS) progressively decrease voluntary motor function, gradually causing communication difficulties. Despite disease progression, a transparent communication board can be used for an extended period as one of the means of communication. It is a transparent plate on which characters including letters, numbers, and symbols are displayed, for caregivers to read intentions of patients. Nonetheless, conventional transparent communication boards have the following problems: 1. the caregiver needs to position each character on the board so that the target character can be aligned linearly between the caregiver's eyes and the patient's eyes; 2. caregivers need to memorize or record words and sentences, because intentions of a patient are read on a character basis; and 3. the arrangement of characters on the board is fixed. The objective of this study was to develop an electronic transparent communication board (device) to solve the problems of conventional transparent communication boards and evaluate and verify its effect. The device included two tablets that were connected with each other via Wi-Fi so that the caregiver could confirm the voluntary movements of the patient by the video images taken by the attached cameras and enter the characters on the screen. Among the three problems of the conventional transparent communication board, the adjustment of the location of the transparent communication board seemed to become easier, because the device can be operated without aligning the visual line of the caregiver with that of the patient. It took longer to operate the prepared device than the conventional transparent communication board, but it is expected that the negative impacts caused by the delays can be reduced, if the communication speed and tablet performance are improved. Characters were considered to become entered more easily with the prepared system than with the approaches depending on memories and notes.