This is the form in which Grendizer combines with its special flying saucer mecha, also known as the "Spaizer." It usually waits in this form at the Institute of Space and Astronautical Science, and when boarding, the pilot enters the cockpit from the top of the mecha.

It was built to support Grendizer, which lacks flight capabilities, and after combining, it is capable of atmospheric flight at Mach 9 and hyperspace flight. Its various weapons easily defeat Mini-Fours. Note that some weapons are unusable in this form. It can also generate a mist called "anti-radar mist" that acts as both a radio jammer and a smokescreen, but this feature is not implemented in SRW.

The Spaizer itself has considerable thrust, and in the main story, it is used in aerial combat with Grendizer mounted on top of the mecha, similar to the sub-flight system in the "Gundam Series."

Although Grendizer's face faces directly forward when combined, the two have separate cockpits. There are an excessive number of processes involved in combining and separating, including moving the seats (some of which seem unnecessary or even skippable), resulting in a loss of 6 seconds, which could be exploited and put the robot in a pinch. For this reason, Dr. Umon developed the Earth-made Spazer to overcome this drawback. From then on, Spazers were mainly used as a means of transportation to the battlefield, and the Earth-made Spazers were responsible for combat.

In addition to the common seat between Grendizer and Spazer, there are also seats that can be used to pilot the Spazer.