A thin film solar cell having adjustable or designable patterns, comprising:a transparent substrate; an upper electrode layer; a photovoltaic layer; and a lower electrode layer. Said upper electrode layer is disposed on said transparent substrate, and said upper electrode layer is a transparent electrode. Said photovoltaic layer is disposed on said upper electrode layer; and said lower electrode layer is disposed on said photovoltaic layer, and said lower electrode layer is provided with said adjustable or designable patterns, so as to achieve purpose of esthetically pleasing, sales promotion, and theft prevention.