The shop - Bubble Works in West Street - has brought the latest craze for bubble tea to the town.
And young people are queueing up to get their hands on the drink.
A spokesman said: “There have been queues outside the door most days.”
Bubble tea, which originated in Taiwan, has been a popular drink in Asian countries since the 1980s.
But it’s now seeing a boom in popularity across the world and is especially geared to the youth market.
Bubble tea itself is a hot or cold tea-based drink made with a choice of milk, fruit and fruit juices with added ‘bubbles’ – soft and chewy tapioca pearls that sit at the bottom.
The often brightly-coloured drink is served in transparent cups with a fat straw so that the tapioca pearls - also known as boba - can be chewed as the tea is swallowed.
The ‘bubble’ refers to both the tapioca and bubbles created by vigorous shaking involved in the blending process.
The new Horsham store is in the process of turning the upstairs into a second kitchen and extra seating area.
The spokesman added that they wanted to make the shop “just a much better space for the youngsters than the normal local coffee shops.”
They are also planning to offer private hire to cater for childrens parties.