As environmental issue of disposable products emerges socially, consumers’ interest in green consumption is increasing. In this study, we focused on the current status and perception of tumbler consumption to find out the perception and practice of green consumption in the MZ generation, paying attention to the positive response and perception of consumers’ green consumption. To this end, a one-on-one in-depth interview was conducted with a total of six people by dividing the tumbler consumption behavior of the MZ generation into four stages: recognition, purchase, use, and disposal. The results of the study are as follows. First, the survey subjects were aware of green consumption, but the level of awareness was not deep, such as not being accustomed to their life patterns. Second, unlike the characteristics of the MZ generation, which pursues consumption that considers the environment, consumer behavior that takes place while thinking about the environment was not revealed. Third, consumers were not using tumblers in the mind of the environment, but rather using them because they needed them, and they were satisfied with the use of tumblers and complained of inconvenience in portability and washing them. Fourth, through the consumer’s disposition of tumblers, it was found that tumblers are left as “good for a gift” rather than “good for the environment”, and there is no deep concern about how to dispose of tumblers for the environment. This study aims to contribute to finding solutions to the mass consumption of disposable products in Korea by identifying the problems of consumers’ use of tumblers through qualitative research and deriving improvement measures and providing ideas for environmental policies for the MZ generation.