Abstract:
Object 
     A cooking apparatus, wherein, independent of the quantity and the temperature of the foodstuff contained in a cooking chamber of the cooking apparatus, the food stuff can be cooked in a consistent time period by initial-heating processing and main-heating processing. 
     Means of Solution 
     A cooking device is provided with a controller for performing initial-heating processing before a transition to main-heating processing. The initial-heating processing is processing which, when the temperature in a cooking chamber is dropped by a foodstuff placed in the cooking chamber, controls supply of electricity to a heater provided in the cooking chamber, and the control is performed such that the temperature in the cooking chamber rises along temperature rising line which defines a temperature rise rate at which the temperature in the cooking chamber reaches a predetermined preset cooking temperature from an initial-heating start temperature, which is set on the basis of a previously determined time period for initial heating, after the time period for initial-heating has elapsed. 
     Selected Figure 
     
       FIG. 7

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    This invention relates to a cooking apparatus. 
         [0002]    1. Background Technologies 
         [0003]    In the Prior Art Publication 1, a cooking apparatus such as steam convection oven is disclosed. The cooking apparatus comprises a cooking chamber for cooking foodstuff, a heater for heating the cooking chamber and a fan for making convectional air flow in the cooking chamber and it is configured to cook a foodstuff contained in the cooking chamber with hot air flow generated by a heater and a fan. In this cooking apparatus, temperature of the cooking chamber is controlled to be predetermined cooking temperature by activating the heater in response to the temperature detected by a cooking chamber temperature sensor. The cooking apparatus controls inside temperature of the cooking chamber as follows; in pre-heating processing, activates the heater to rise the inside temperature of the cooking chamber up to the temperature suitable for cooking the foodstuff in response to the temperature detected by the cooking chamber temperature sensor. After the pre-heating processing is completed, when the inside temperature of the cooking chamber is dropped by placing the foodstuff in the cooking chamber, it activates the heater to rise inside temperature of the cooking chamber up to predetermined cooking temperature in response to the temperature detected by the cooking chamber temperature sensor as initial-heating processing. After the initial-heating processing is completed, it activates the heater to maintain inside temperature of the cooking chamber at predetermined cooking temperature during predetermined cooking time period as main-heating processing. 
         [0004]    2. Prior Art 
         [0005]    Patent Publication 1: Japanese Laid-open Publication No.2002-364852 
       DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
       [0006]    In the cooking apparatus of Patent Publication 1, initial-heating processing is performed to resume cooking chamber temperature up to predetermined cooking temperature when the cooking chamber temperature is dropped by foodstuff being placed in the cooking chamber after the pre-heating processing. However, the time period required for resuming the cooking chamber temperature may vary depending on the mass and temperature of the foodstuff. The variety of heating time in initial heating process may result uneven quality of cooked foodstuff Therefore, a user must check the condition of the foodstuff during main-heating processing and it is troublesome. 
       Means to Solve the Problem 
       [0007]    An object of the present invention is to provide a cooking apparatus comprising a cooking chamber which made to contain a foodstuff inside, a heater for heating interior of said cooking chamber, an electric fan generating convectional air flow in the cooking chamber, a cooking chamber temperature sensor for detecting inside temperature of cooking chamber, cooking temperature setting means for preset cooking temperature suitable for foodstuff contained in the cooking chamber and a controller for controlling inside temperature of the cooking chamber by performing a pre-heating processing which rises inside temperature of the cooking chamber up to said predetermined cooking temperature by controlling electricity supply for the heater in response to value detected by the cooking chamber temperature sensor before said foodstuff being placed in the cooking chamber and a main-heating processing which rises and maintains inside temperature of cooking chamber at said predetermined cooking temperature by controlling electricity supply for the heater in response to value detected by the cooking chamber temperature sensor when the inside temperature of the cooking chamber is dropped by the food stuff being place in the cooking chamber. Wherein, said controller comprising a control means performing an initial-heating processing before transition to said main-heating processing which rises inside temperature of the cooking chamber being match with a temperature rising line that regulates temperature rising rate which provided in relation of elapsed time in predetermined initial-heating processing time period and temperature change from initial-heating start temperature to said preset cooking temperature in response to temperature detected by the cooking chamber temperature sensor when the inside temperature of the cooking chamber is dropped by the food stuff being place in the cooking chamber. 
         [0008]    In a cooking apparatus described above, which comprises a control means performing the initial-heating processing before a transition to the main-heating processing which rises inside temperature of the cooking chamber to be match with a temperature rising line that regulates temperature rising rate which provided in relation of elapsed time in predetermined initial-heating processing time period and temperature change from initial-heating start temperature to said preset cooking temperature in response to temperature detected by the cooking chamber temperature sensor, it is possible to make the duration of foodstuff being cooked during initial-heating processing and main-heating processing consistent, even if the quantity and/or temperature of the foodstuff being placed in the cooking chamber varies. Thus, it is possible to achieve constant quality of cooked foodstuff. 
         [0009]    In a cooking apparatus according to the present invention, it is preferred to comprise a steam generating device for supplying steam into said cooking chamber and said controller comprising a control means for controlling electricity supply for an electric heating means in the steam generating device together with said heater in response to value detected by the cooking chamber temperature sensor during said initial-heating processing. In this case, the foodstuff placed in the cooking chamber can be cooked with hot air flow generated by the heater and the fan or steam generated by steam generating device and with combination of these two. Also in this case, steam generating device is controlled by the controller, thus supply amount of steam into the cooking chamber can be controlled. Moreover, it is possible to provide better accuracy of cooking temperature control by controlling the supply of electricity to the heater and the steam generating device variably, thus the heater and the steam generating device can be activate simultaneously within the limit of electricity capacity provided with the cooking apparatus, in comparison with one that activate those in alternately. 
         [0010]    In the case the inside temperature of said cooking chamber does not drop below the initial-heating start temperature when the foodstuff is placed in the cooking chamber, because of the quantity of the food stuff is small and/or temperature of the food is high, said controller stops supply of electricity to said heater until the cooking chamber temperature detected by the cooking chamber temperature sensor being match with the temperature rising line, thus the foodstuff can be cooked in consistent initial heating time period under control of said controller. 
         [0011]    The cooking apparatus according to the present invention may be provided with a manual mode and a program mode. The manual mode, in which, cooking temperature and time period of main-heating processing can be set by a user. The program mode, in which, cooking temperature and time period of main-heating processing is preset. When the manual mode is selected, cooking can be done in conventional style which, the user checks progression during cooking. When the program mode is selected, the cooking apparatus performs the initial-heating processing and main-heating processing to provide consistent quality of the cooked foodstuff. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a front view of the cooking apparatus of the present invention. 
           [0013]      FIG. 2  is a A-A line cross-sectional view in  FIG. 1 . 
           [0014]      FIG. 3  is a B-B line cross-sectional view in  FIG. 2 . 
           [0015]      FIG. 4  is a C-C line cross-sectional view in  FIG. 2 . 
           [0016]      FIG. 5  is a plan view of operation panel. 
           [0017]      FIG. 6  is a block diagram illustrates control device of the cooking apparatus of the present invention 
           [0018]      FIG. 7  is a chart shows temperature and output of the heater during pre-heating process, initial-heating process and main-heating process in oven cooking mode (1). 
           [0019]      FIG. 8  is a chart shows temperature and output of the heater during pre-heating process, initial-heating process and main-heating process in oven cooking mode (2). 
           [0020]      FIG. 9  is a chart shows temperature and output of the heater during pre-heating process, initial-heating process and main-heating process in combined cooking mode. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Hereinafter describe a steam convection oven which is an embodiment of cooking apparatus of the present invention referring to the drawings. A steam convection oven  10  comprises a cooking chamber  11  for accommodating foodstuff inside, a heater  20  for heating interior of the cooking chamber  11 , an electric fan  30  for generating convectional flow of air heated by the heater  20  in the cooking chamber, a cooking chamber temperature sensor  13  for detecting interior temperature of the cooking chamber, a cooking temperature setting means for setting optimal temperature for cooking the foodstuff placed in the cooking chamber and a controller  70  for performing a pre-heating processing which preliminary rise the cooking chamber temperature up to preset cooking temperature by controlling supply of electricity to the heater  20  in response to the value detected by the cooking chamber temperature sensor  13  before the foodstuff being placed in the cooking chamber, and after the pre-heating processing, a main-heating processing which maintain the cooking chamber temperature at preset cooking temperature by controlling supply of electricity for the heater  20  in response to the value detected by the cooking chamber temperature sensor  13  when the cooking chamber temperature dropped after the foodstuff being placed in the cooking chamber  11 . The controller  70  of the steam convection oven  10  comprises control means for performing an initial-heating process before a transition to the main-heating processing. The initial-heating processing which rises inside temperature of the cooking chamber  11  to be match with a temperature rising line that regulates temperature rising rate which provided in relation of elapsed time in predetermined initial-heating processing time period and temperature change from initial-heating start temperature to said preset cooking temperature in response to temperature detected by the cooking chamber temperature sensor  13  when the inside temperature of the cooking chamber is dropped by the food stuff being place in the cooking chamber  11 . 
         [0022]    The cooking apparatus  10  according to this embodiment has oven cooking mode, steam cooking mode and combined cooking mode. In the oven cooking mode, the foodstuff placed in the cooking chamber  11  is cooked with hot air flow generated by the heater  20  and the electric fan  30 . In the steam cooking mode, the foodstuff placed in the cooking chamber  11  is cooked with steam that comes from the electric fan  30  and the steam generating device  40 . In the combined cooking mode, cooking is done with hot air flow and steam generated by the heater  20 , the electric fan  30  and the steam generating device  40 . The cooking apparatus  10  has manual mode and program mode. In the manual mode, cooking modes described above, cooking temperature, steam thickness and main-heating time period are free to choose to suite cooking method for a foodstuff. In the program mode, cooking modes described above, cooking temperature, steam thickness and main-heating time period are preset according to the cooking method for a foodstuff 
         [0023]    As illustrated in  FIGS. 1 and 2 , cooking chamber  11  is made to accommodate foodstuff for cooking. It has an opening in front face of box shaped outer shall and heat insulated door  12  is mounted for foodstuff to go through there. In the cooking chamber  11 , a cooking chamber temperature sensor  13  utilizing thermocouple is placed for detecting inside temperature of cooking chamber  11 . As illustrated in  FIGS. 2 and 3 , the cooking chamber  11  comprises a steam inlet  11   a  a passage for steam generated by steam generating device  40 , a port  11   b  for air to go in and out from the cooking chamber  11  and a port  11   c  for draining water from the cooking chamber  11 . The port  11   c  provided in cooking chamber  11  is connected with a drain tube  14 . The drain tube  14  is connected with a drain tank  15  also act as drainage for steam generating device  40 . The air in the cooking chamber  11  containing steam is discharged through drain tube  14  and drain tank  15 . An exhaust temperature sensor  16  is provided in the drain tube  14  for detecting temperature of exhaust air. 
         [0024]    As illustrated in  FIGS. 2 and 3 , the heater  20  is a conventional electric heater such as sheathed heater for heating interior of the cooking chamber  11  with supplied electricity and is disposed inside left wall of the cooking chamber  11  in circular shape. 
         [0025]    As illustrated in  FIGS. 2 and 3 , the electric fan  30  is a centrifugal fan such as sirocco fan for generating convectional air flow in the cooking chamber  11  with supplied electricity and is mounted on the left inside wall of the cooking chamber. The electric fan  30  is surrounded by the heater  20  which disposed in a circular shape. The electric fan  30  driven by a fan motor  31  blows the air onto the heater  20  to generate convectional flow of hot air in the cooking chamber  11 . 
         [0026]    As illustrated in  FIGS. 2 and 4 , steam generating device  40  which supply steam into the cooking chamber  11  with supplied electricity and is disposed left side position of the cooking chamber in a casing  10   a.  The steam generating device  40  is an induction heating type steam generating device which comprises cylindrical shape steam generating vessel  41 , an induction heater body consists of metallic stick shape electro conductive material disposed inside of the steam generating vessel  41  and an induction heating coil  42  wound around outer peripheral of the steam generating vessel  41 . The heating coil  42  supplied with high frequency electric current heats the heater body to evaporate the water in the steam generating vessel  41  thus the steam generating device  40  generates steam. A steam supply tube  43  is disposed on the upper end of the steam generating vessel  41 . The steam generated in the steam generating vessel  41  is flow into the cooking chamber  11  through the steam supply tube  43 . The bottom end of the steam generating vessel  41  is attached to the drain tank  15  for draining the water in the cooking chamber  11 . The water in the steam generating vessel  41  is discharged to outside through drain tank  15 . 
         [0027]    As illustrated in  FIGS. 2 and 4 , a vent device  50  is provided which comprises vent tube  51 , vent valve  52  consists of butterfly valve disposed in the vent tube  51  and a vent valve motor  53  for activating the vent valve  52 . The vent tube  51  is connected with the port  11   b  disposed in the left side wall of the cooking chamber  11  and back side of the electric fan  30 . The vent valve  52  is rotatably disposed in the middle portion of the vent tube  51  and is driven by the vent valve motor  53  to vary its opening for adjusting the air flow through the vent tube  51 . When the vent valve  52  of the vent device  50  opened with the electric fan  30  running, the air outside the cooking chamber  11  is introduced into the cooking chamber  11  through the vent tube  51 . When the vent valve  52  opened with the electric fan  30  is not running, the air in the cooking chamber exhausted to the outside of the cooking chamber  11  by the steam supplied by steam generating device  40  or the steam vapored from the foodstuff through the vent tube  51 . 
         [0028]    As illustrated in  FIGS. 1 and 5 , an operation panel  60  is provided for setting cooking mode, cooking temperature and cooking time (main-heating time period). The operation panel  60  comprises “Steam”, “Hot Air” and “Combination” buttons. These buttons are provided for selection of cooking modes which are steam cooking mode, oven cooking mode and combined cooking mode in manual cooking. The operation panel  60  comprises “Cooking Time” and “Cooking Temperature” buttons. These buttons are provided for setting cooking time (main-heating time period) and cooking temperature. The operation panel  60  comprises “Select” and “Menu” buttons. These buttons are provided for selecting pre-programmed cooking programs in the program mode in which said cooking mode, cooking temperature and cooking time (main-heating time period) are preset. 
         [0029]    As illustrated in  FIG. 6 , the cooking apparatus  10  comprises the cooking chamber temperature sensor  13 , the exhaust temperature sensor  16 , the heater  20 , the fan motor  31 , the steam generating device  40 , the vent device  50  and a controller  70  having microcomputer  71  which is connected with the operation panel  60 . The controller  70  comprises a memory  72  and a timer  73 . The cooking program in the program mode and temperature rising line during initial-heating processing are stored in the memory  72 . The timer  73  is provided for counting elapsed time during initial-heating processing and main-heating processing. In this embodiment, temperature rising line is provided in relation of elapsed time of initial-heating processing and temperature range from initial-heating processing start temperature to preset main-heating processing temperature. 
         [0030]    The controller  70  comprises drive circuits  74 - 76 , which are connected to the heater  20 , the fan motor  31  and the steam generating device  40 . The driving circuit  74  is a phase control circuit, which changes electricity supply for the heater  20  by changing phase of voltage. The driving circuit  75  and  76  are inverter circuits, which changes electricity supply for the fan motor  31  and the steam generating device  40  by increasing or decreasing driving time of switching element. The controller  70  controls output of the heater  20 , speed of the fan motor  31  and steam amount of the steam generating device  40  by means of the driving circuits  74 - 76  variably control the input electricity for the heater  20  , the fan motor  31  and steam generating device  40 . In this embodiment, the driving circuits  74 - 76  are utilizing phase control circuit and inverter circuit. However, it is not limited to these. The variable control of supply electricity for devices  20 ,  31  and  40  may be accomplished by utilizing other circuit 
         [0031]    The controller  70  comprises a control means which controls activation of the heater  20  as follows; rise the inside temperature of the cooking chamber  11  up to preset cooking temperature suitable for cooking the foodstuff in response to the temperature detected by the cooking chamber temperature sensor  13  in the pre-heating processing as the pre-heating processing, after the pre-heating processing, when the inside temperature of the cooking chamber  11  dropped by placing the foodstuff in the cooking chamber  11 , rise the inside temperature of the cooking chamber  11  up to the preset cooking temperature again as the initial-heating processing and then after the initial-heating processing is completed, maintain the inside temperature of the cooking chamber  11  at preset cooking temperature during predetermined main-heating processing time period in response to the temperature detected by the cooking chamber temperature sensor  13 . 
         [0032]    The controller  70  comprises a control means for controlling activation of the heater  20  to rise the inside temperature of the cooking chamber  11  being match with the temperature rising line that regulates temperature rising rate which provided in relation of elapsed time in predetermined initial-heating processing time period and temperature change from initial-heating start temperature to said preset cooking temperature. The controller  70  is programed not to perform above-mentioned initial-heating processing when the manual mode is selected. 
         [0033]    Hereafter, describe how the cooking apparatus  10  works in the oven cooking mode and the combined cooking mode under the programed mode. As illustrated in  FIG. 7 , in the oven cooking mode under the programed mode, the controller  70  controls electricity supply for the heater  20  to rise the inside temperature of the cooking chamber  11  up to preset cooking temperature (250 degree centigrade in this embodiment) in response to the temperature detected by the cooking chamber temperature sensor  13 . When the inside temperature of the cooking chamber  11  reached to the preset cooking temperature, the controller  70  controls electricity supply for the heater  20  to maintain the preset cooking temperature as follows; when the detected temperature at cooking chamber temperature sensor  13  is higher than the predetermined upper limit temperature (255 degree centigrade in this embodiment), decrease electricity supply for the heater  20  by the driving circuit  74  and when the detected temperature at the cooking chamber temperature sensor  13  is lower than the predetermined lower limit temperature (245 degree centigrade in this embodiment), increase electricity supply for the heater  20  by the driving circuit  74 . 
         [0034]    After pre-heating processing completed, the inside temperature of the cooking chamber  11  may drop down to initial-heating start temperature (150 degree centigrade in this embodiment) by placing the foodstuff in the cooking chamber  11 . The controller  70  performs above described initial-heating processing, so that the electricity supply for the heater  20  is controlled to match the inside temperature of the cooking chamber  11  with the temperature rising line stored in the memory  72 . That is, the controller  70  controls the inside temperature of the cooking chamber to match with the temperature rising line as follows; increase the electricity supply for the heater  20  by the driving circuit  74  when the temperature detected by the cooking chamber temperature sensor  13  is lower than the temperature rising line and decrease the electricity supply for the heater  20  by driving circuit  20  when the temperature detected by the cooking chamber temperature sensor  13  is higher than the temperature rising line. 
         [0035]    As illustrated in  FIG. 8 , the inside temperature of the cooking chamber  11  does not always drop. When temperature of a foodstuff is high, inside temperature of the cooking chamber may not drop down to initial-heating starting temperature. In this case, the controller  70  controls the inside temperature of the cooking chamber  11  in response to temperature detected by the cooking chamber temperature sensor  13  by not activating the heater  20  until detected temperature is going to match with the temperature rising line. After inside temperature of the cooking chamber  11  detected by the cooking chamber temperature sensor  13  falls on to the temperature on to the temperature rising line, the controller  70  maintains the inside temperature of the cooking chamber detected by cooking chamber temperature sensor  13  being match with the temperature rising line by controlling the heater  20 . 
         [0036]    After the initial-heating processing completed, the controller  70  maintains inside temperature of the cooking chamber  11  at preset cooking temperature during time period of the main-heating processing by controlling activation of the heater  20 . That is, the controller  70  maintains inside temperature of the cooking chamber  11  at preset cooking temperature during time period of main-heating processing as follows; when temperature detected by the cooking chamber temperature sensor  13  reached the upper limit temperature which is predetermined degrees higher than the preset cooking temperature, decrease electricity supply for the heater  20  by the driving circuit  74 , when detected temperature at cooking chamber temperature sensor  13  reached the lower limit temperature which is predetermined degrees lower than the preset cooking temperature, increase electricity supply for the heater  20  by the driving circuit  74 . 
         [0037]    Next, in the combined cooking mode under the program mode, as illustrated in  FIG. 9 , same as described in the oven mode, the controller  70  activates the heater  20  to rise the inside temperature of the cooking chamber  11  up to the preset cooking temperature (250 degree centigrade in this embodiment) in response to the detected temperature at cooking chamber temperature sensor  13  in the pre-heating processing. After the pre-heating processing is completed, the inside temperature of the cooking chamber  11  drop down to nearby predetermined initial-heating start temperature (150 degree centigrade in this embodiment) by placing the foodstuff in the cooking chamber  11 . The controller  70  performs the initial-heating process during initial-heating time period, controls the heater  20  to make inside temperature of the cooking chamber  11  being match with the temperature rising line stored in the memory  72 . That is, the controller  70  controls the inside temperature of the cooking chamber  11  matching with the temperature rising line as follows; when the temperature detected by the cooking chamber temperature sensor  13  being lower than the temperature rising line, increase electricity supply for the heater  20  by the driving circuit  74  and when the temperature detected by the cooking chamber temperature sensor  13  being higher than the temperature rising line, decrease electricity supply for the heater  20  by the driving circuit  74 . The controller  70  temporally activates the steam generating device  40  together with the heater  20  within the limit of electricity capacity regulated to the cooking apparatus  10  in the beginning of the initial-heating processing. Also, in the initial-heating processing of the combined cooking mode, when the foodstuff placed in the cooking chamber is small in amount or the temperature of the foodstuff is high, the controller  70  does not activate the heater  20  until the temperature detected by the cooking chamber temperature sensor  13  matches with the temperature rising line as same as described above in the initial-heating processing of the oven mode. 
         [0038]    After the initial-heating processing is completed, the controller  70  controls activation of the heater  20  and the steam generating device  40  to maintain predetermined cooking temperature and predetermined steam thickness in the cooking chamber  11  during main-heating processing time period in main-heating processing. That is, the controller  70  maintains inside temperature of the cooking chamber  11  at preset cooking temperature during predetermined main-heating processing time period as follows; when temperature detected by the cooking chamber temperature sensor  13  reached the upper limit temperature which is predetermined degrees higher than the preset cooking temperature, decrease electricity supply for the heater  20  by the driving circuit  74 , when detected temperature at cooking chamber temperature sensor  13  reached the lower limit temperature which is predetermined degrees lower than the preset cooking temperature, increase electricity supply for the heater  20  by the driving circuit  74 . The controller  70  maintains the thickness of steam at preset steam thickness by controlling electricity supply for the steam generating device  40  through the driving circuit  76  in response to the temperature detected by the exhaust temperature sensor  16  within the electricity capacity regulated to the cooking apparatus  10 . 
         [0039]    In the cooking apparatus  10  constructed as described above, the controller  70  comprises the control means for controlling activation of the heater  20  to rise the inside temperature of the cooking chamber  11  being match with the temperature rising line which provided in relation of elapsed time in predetermined initial-heating processing time period and temperature change from initial-heating start temperature to preset cooking temperature. So that, it is possible to make cooking time period consistent even if the quantity and/or temperature of the foodstuff placed in the cooking chamber  11  varies. Thus, it is possible to achieve constant quality of cooked foodstuff without a user who frequently checking the cooking condition. 
         [0040]    In the cooking apparatus  10  as described above, the temperature inside the cooking chamber  11  can be controlled in high accuracy, because the controller  70  comprises driving circuit  74  which variably controls input electricity to the heater  20 . The controller  70  variably controls input electricity to steam generating device  40  through driving circuit  76  to control the amount of steam supply into the cooking chamber  11 . Moreover, it is possible to provide better accuracy of cooking temperature control by controlling the supply of electricity to the heater and the steam generating device variably, thus the heater and the steam generating device can be activate simultaneously within the limit of electricity capacity provided with the cooking apparatus (the hatched area depicted in  FIG. 9  shows electricity capacity), in comparison with one that activate those in alternately. 
         [0041]    In the cooking apparatus  10 , it controls the heater  20  not to activate until the detected temperature from the cooking chamber temperature sensor  13  to go match with the temperature rising line when the inside temperature of the cooking chamber  11  detected by cooking chamber temperature sensor  13  is higher than the initial-heating start temperature. Thus, the foodstuff can be cooked in consistent initial-heating time period even when the quantity of the foodstuff is small and/or the temperature of the foodstuff is high. 
         [0042]    In the cooking apparatus  10 , it is selectable to perform the initial-heating process or not. When initial-heating process performing is chosen, quality of the cooked foodstuff is consistent. When no initial-heating process is chosen, the conventional style cooking which the user checking the progression of cooking is possible. That is, two way of cooking can be done with single cooking apparatus. 
         [0043]    In the cooking apparatus  10 , it is selectable between the manual mode and the program mode. The manual mode, in which, cooking temperature and time period of main-heating processing can be set by a user. The program mode, in which, cooking temperature and time period of main-heating processing is preset. When the manual mode is selected, cooking can be done in conventional style which, the user checks progression during cooking. When the program mode is selected, the cooking apparatus performs the initial-heating processing and main-heating processing to provide consistent quality of the cooked foodstuff. Further, in this embodiment, selection of perform or not perform the initial-heating process is done by selection of manual mode or program mode. Buttons for selecting perform or not to perform the initial-heating process may be provided on the control panel  60 . 
         [0044]    In the embodiment described above, the controller  70  variably controls the input electricity for the heater  20  through driving circuit  74  to rise the inside temperature of the cooking chamber 11  to go match with the temperature rising line. The invention is not limited to this embodiment, the controller  70  may control the heater  20  by on and off. In this case, control accuracy may be low compared to the one variably controlling the electricity supply to the heater  20 , however, it is possible to rise the inside temperature of the cooking chamber  11  to go match with the temperature rising line. 
       REFERENCE OF NUMERALS 
       [0045]      10  . . . Cooking apparatus (Steam convection oven),  11  . . . Cooking chamber,  20  . . . Heater,  30  . . . Fan,  40  . . . Steam generating device,  70  . . . Controller,  74 ,  76  . . . Driving circuit