An ignition apparatus includes a blow-off determining unit. The blow-off determining unit determines, when a secondary electric current drops below a predetermined threshold value Ia during a determination period, that blow-off has occurred; the determination period is a predetermined time period ΔT from the start of a spark discharge by a main ignition circuit. Further, when it is determined that blow-off has occurred during a main ignition (full-transistor ignition), it is controlled to perform a continuing spark discharge after the main ignition in a next cycle. Moreover, a secondary electric current command value I2a in performing the continuing spark discharge is set to an electric current value that is obtained by adding a predetermined electric current value α to the predetermined threshold value Ia used in the blow-off determination. Consequently, in the next cycle, it is possible to reliably prevent blow-off, thereby reliably preventing a misfire.