The purpose of this study is to present a STEM activity designed to develop students' scientific process and entrepreneurship skills in accordance with the problem-based teaching method focused on chemistry courses and their implementation stages. The design of the activity is based on a real-life problem related to the learning outcomes in the chemistry curriculum. The use of smart packaging, which is widely used in some countries abroad, is not yet widespread in our country. Smart packages are systems that inform consumers about the freshness of food. In the STEM activity initiated with a story, students were asked to design and prototype a smart packaging that is harmless to human health with cheap and easily accessible materials given to them and to carry out the promotion and marketing of the product they created. STEM worksheet applications, which include questions and directions that will enable students to work in accordance with scientific research steps, include application stages aimed at providing students with 21st-century skills such as teamwork, problem-solving, communication, entrepreneurship, and design. The students who participated in the activity described it as interesting.