Motivation is one of the main determinants in the success of attaining a foreign language. Accordingly, there has been a considerable amount of research on L2 motivation in the last three decades. These studies on L2 motivation, however, tend to depend heavily on quantitative approach rather than qualitative approach regardless of educational context. Although we have gained our knowledge on relationships among motivational factors, we do not have enough evidence to understand Korean learners’ L2 motivational ups and downs in a classroom foreign language learning. Suspending our current beliefs about L2 motivation, and investigating what facilitate, debilitate, and sustain learners’ motivation in a Korean classroom will provide us invaluable insights to understand the nature of L2 motivation. The purpose of this paper is to find out factors that is facilitating, debilitating, and maintaining learners’ motivation in an ESP classroom in a university. The participants were 115 university students enrolled in a business English class. The participants’ responses on the open-ended questionnaire were analyzed by the NUD*IST program (V.4.0). There seem to be some difference in facilitating, debilitating, sustaining motivations in learning English in classroom. Classroom implications are discussed in light of these findings.