SURFACE TREATMENT APPARATUS

PURPOSE:To shorten the time required for taking a boat into and taking it out of a reaction furnace and to enhance the treatment capacity of an apparatus by a method wherein, when a boat elevator is ascended, an instruction device changes a speed instruction to a low-speed instruction or a high-speed instruction when a position detection signal coincides with a first intermediate position or a second intermediate position. CONSTITUTION:A boat 17 is ascended and descended at a low speed VL until the boat 17 is housed completely inside a reaction furnace 10 after the upper end of the boat 17 has reached the opening part of the reaction furnace 10 and until the boat 17 is taken out completely to the outside of the reaction furnace 10 after the upper end of the boat 17 has reached the opening part of the reaction furnace. A transfer device 18 is driven at high speed except a retreat section required to retreat the transfer device until the upper end of the boat 17 is ascended and reaches the opening part of the reaction furnace and until the upper end of the boat 17 is descended and reaches the opening part of the reaction furnace 10. The time required to take the boat 17 into and take it out from a boat delivery position SZ can be shortened as compared with a case where a boat elevator 12 is driven at the constant speed VL over the whole range from the lowermost descended position SD up to the uppermost ascended position SU until the boat 17 reaches a prescribed position inside a quartz tube 13.