We present the latest results of the use of soluble materials such as organic semiconductors (OSCs) or gate-dielectrics for simplified processing of organic thin-film transistors (OTFTs). In this paper, we described our fabrication of a solution-processed OTFT with 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) as the OSC and siloxane-based spin-on glass (SOG) as the inorganic gate-dielectric. Also, synthesized TIPS-pentacene and SOG were examined for use as the OSC and gate-dielectric in an OTFT. From electrical measurements, we obtained device performance characteristics such as charge carrier mobility, threshold voltage, current ON/OFF ratio, and subthreshold swing, which were 6.48 times 10-3 cm2/V ldr s, -13 V, ~100, and 1.83 V/dec, respectively.