This observation aims to explain the importance of confidance and it's correlation toward student's concept mastering in learning process activity by inquiry learning model application to the grade five of SDN Sugih Waras 6 Madiun by the number of 21 student's that consistof 12 female students and 9 male students. The type of observation which is used is class action abservation which consists of 4 phases, starting from planning, action, observation, and reflection. Observation result is got by observing, testing, and questionnaire distribution. Moreover, teacher and students activity is analyzed in from of percentage by the observation of exist indicators. While the students mastering concept data is analyzed by the percentage of studying success classically. Observation result shows that teachers activity during the learning process on first cycle and second cycle gained 100%, and can be seen that there is adecline. It can be seen that teachers activity can be maintained and not decreased. Furthermore, students activity while joined the learning process on first cycle gained 85,51% and on second cycle gained 91,38%, it increase 5,87%. Confidance questionnaire increased 8,66%, in the first cycle gained 74,5%, while the second cycle gained 83,16%. Next, concept mastering of LP product increased 61,43%, from 28,57% with the average 61 in first cycle became 90% with the average 79,77 in second cycle. So, it can be concluded that inquiry learning model can be applied in Natural Sciences subject with the materials that apply light characters by making arts or model. Based on this observation result so Elementary School teachers are suggested to try applying inquiry learning model in delivering Natural Science to incease the confidance and students concept matering.