If he is afraid of spiders, our seemingly fearless leader wasn't showing it.

Prime Minister John Key jumped at the chance to get up close and personal with Gertrude the Mexican red-kneed tarantula when opening the new Biological Sciences Research Building at Canterbury University this morning.

Mr Key let the spider take a seat on his hand and arm, and even brought it up near his face for a close look, as the media's cameras surrounded him.

He later joked to an audience that if he had been asked that when he put his hand up to be Prime Minister, he would have to put his hand out for a tarantula, he might not have applied for the job.

"But I have, and I have survived. I'm not sure who was more worried - Gertrude the tarantula, or myself. But we managed to both get through it with aplomb."