AbstractSingle‐layer fuel cells (SLFCs) are the product of recent advances in low‐temperature solid‐oxide fuel cell (SOFC) research and development. Conventional three‐layer materials comprising an anode, an electrolyte, and a cathode have been replaced by one‐layer materials that can integrate all of the functions of fuel cell anodes, electrolytes, and cathodes into one function. Excellent performance, simple technology, and ultra‐low cost have increased the potential of SLFCs for commercialization. Therefore, methods should be developed to scale up this innovative and advanced SOFC technology for engineering use and further commercial applications. This work reports the scaling up of an SLFC through powder material preparation, pulp preparation and tape casting, cold‐press shaping, hot pressing, and final surface reduction to fabricate 6 cm×6 cm engineering cells with an active area of 25 cm2. Each SLFC delivers approximately 10 W of power at 525–550 °C. The performance of the device is comparable with or even better than that of conventional SOFCs. A maximum output power of 12.0 W (0.48 W cm−2) is obtained from the 6 cm×6 cm SLFC at 550 °C. This study develops a scaling‐up technology that uses tape casting and hot pressing to enhance the commercial uses of SLFC.