This study aims to examine the current state of wearing working clothes for the workers who work in Electric Technology Division, Korea Railroad Corporation, to identify inconveniences and problems in relation to the working clothes, and based on the examination, to find a way to improve them, creating a design of summer working clothes that will have more advanced functionalities including activity adaptability and comfort. Survey was conducted through direct observation and interview for Electric Railway Power Team. A total of 352 copies were collected and analyzed. Based on the results of questionnaire, an experimental clothes, the functionality of which has improved in terms of design, material, and patterns, was created. The followings are the results of the study. Easy activity, design, and comfort are required as functions of working clothes. In design related questions, the survey shows high dissatisfaction in the color of existing working clothes, and preferred colors are dark blue and gray. With regard to the method of zipping up the front side, zippers are preferred. Although many pockets on the existing working clothes have high satisfaction, dissatisfaction to pocket format is high. In material related questions, lower dissatisfaction is indicated for the sense of touch, ventilation and sweat absorption. It is shown that the areas frequently polluted include the lower part of pocket, the edges of sleeves and elbow areas on the jacket. The frequently polluted area of the trousers include knee areas, the edges of pants and buttocks. With regard to the areas where the workers felt discomfort when motion, discomfort is highly indicated with armpits and back on the jacket. Also discomfort is highly indicated with crotch, buttocks and knee areas on the trousers. In material related questions, lower dissatisfaction is indicated for the sense of touch, ventilation, sweat absorption.