<human>:  Who was the first person to see bacteria with a microscope?
<bot>: Antonie van Leeuwenhoek was the first person to see bacteria with a microscope. He was a Dutch scientist who made significant contributions to microbiology and microscopy. He discovered many new species of bacteria and invented the first microscope in 1674. He also invented a method for producing saltpeter, a key ingredient in gunpowder.