We have developed a manufacturing technology for single-crystal thin films of organic semiconductors at arbitrary positions on the surface of sheets using a novel inkjet printing technique. The technique uses alternating print deposition of microliquid droplets both of ink composed of a dissolved organic semiconductor and of another ink that prompts crystallization of the organic semiconductor. The technology allows producing single-crystal thin films of an organic semiconductor, C₈-BTBT, with molecularly flat surfaces, and thereby improving performance of thin-film transistors (TFTs) that are indispensable building blocks for large-area electronics products such as flat displays. The performance of the device is 100 times as high as that of TFTs fabricated by conventional printing methods. It is expected that the technology would greatly accelerate the research and development of flexible electronic devices.