The importance of the validity and reliability in measuring the research instrument is to prove that the data collection through the questionnaires is valid. This study aimed to measure the validity and reliability of the questionnaire on the relation of safety climate factors and their relationship with personal attributes in the small and medium enterprise (SMEs) wood based furniture industries. The object of this study was 100 wood workers taken in the center of SMEs furniture industry in Indonesia such as Jepara, Sukoharjo, Sragen and Surakarta. The questionnaire consisted of 36 items with 8 variables. Method of taking the data in this research was using judgment sampling. In measuring the test of the validity of the questionnaire, Pearson Product Moment test was used, while to measure the reliability test Cronbach's Alpha was used. The results of this study showed 36 items in the questionnaire  were valid based on the value of Pearson Product Moment of ≥0.72. This indicated that the items in this questionnaire could represent the object of this study. The reliability test showed Cronbach's Alpha value of 0.98. These results showed that the items in this research questionnaire were able to deliver relatively consistent results when repeatedly tested. It could be concluded that the items in this questionnaire were valid and reliable for measuring safety climate factors  in SMEs wood based furniture industries.