Middle meningeal arteriovenous fistula (MMAVF) is a shunt between the middle meningeal artery and the vein surrounding the artery. We report an extremely rare case of spontaneous MMAVF; then, we evaluated the effectiveness of trans-arterial embolization for spontaneous MMAVF and the possible cause of spontaneous MMAVF. A 42-year-old man with tinnitus, a left temporal headache, and pain surrounding the left mandibular joint was diagnosed with MMAVF on digital subtraction angiography. Trans-arterial embolization with detachable coils was conducted, which resulted in a fistula closure and symptoms' diminishment. The cause of MMAVF was thought to be the rupture of the middle meningeal artery aneurysm. A middle meningeal artery aneurysm can be a cause of spontaneous MMAVF, and trans-arterial embolization might be an optimal treatment.