Essential mask products during this pandemic directly benefits the mask business in the form of increased mask products sales. This condition requires business people to offer masks that function as personal protective equipment, and they also consider product design and product custom. The goal is to tempt customers into buying mask products that, in addition to their needs, also meet their interests. Besides, advances in internet technology have made its use increase. The increase is from the aspect of usage intensity to the level of browsing to internet-based media. The internet makes customers, especially the millennial generation, have more and more information making purchase decisions, namely for mask products. Therefore, this study uses a quantitative approach with multiple regression analysis. A sampling of 128 millennial generation respondents used the accidental sampling method, namely accidental sampling of prospective respondents so that consideration of the requirements’ suitability must be fulfilled. Based on the results of data analysis, it was found that: 1). product design has a positive and significant effect on purchasing decisions; 2) product custom has a positive and significant effect on purchasing decisions; and 3) product design and custom have a positive and significant effect on purchasing decisions. The purpose of this research is to answer questions about purchasing decisions based on the design and custom of mask products.