Teacher’s sense of humor is like a miracle in creating effective teaching and learning environments where there is no place for stress and anxiety but instead intrinsic motivation is enhanced. The present study aims mainly, to explore the effects of teachers’ sense of humor of EFL intermediate learners' reading comprehension ability. Having administered a test of reading proficiency, 58 learners are selected and assigned into control and experimental groups. Also two English language teachers, based on TOEFL and Humor Questionnaire, are selected to teach these learners. The process of teaching and the materials were the same for both groups. But participants in humor class were taught in a well-defined humorous environment managed by the teacher. Considering the control group, the process of teaching reading texts was conducted in a normal manner. To measure the relationship between EFL teachers’ sense of humor and EFL learners' intrinsic motivation in reading comprehension ability, an Intrinsic Motivation in Reading Questionnaire (IMERQ) including reading curiosity, is given to experimental participants both at the outset and at the end of the course. Finally based on the data, it was found that teachers’ sense of humor was effective in improving learners' reading comprehension ability and enhancing intrinsic motivation. The findings can also provide pedagogical implications for considering teachers’ sense of humor as an intrinsically motivating learning tool.